Dr Brien said they were now searching for a crocodile measuring more than four metres.

"It's an aggressive animal and so we'll do what we need to do to remove it. We may capture it through conventional means, but lethal force is an option," Dr Brien said.

In a separate incident before dawn on Sunday, Lee de Paauw was mauled after acting on a dare to swim at night in the croc-infested Johnstone River.

The 18-year-old is recovering in hospital after undergoing surgery on his arm.

Last week the Queensland government updated its crocodile management strategy, replacing several existing programs with a single framework for the state's north.

Dr Brien said renewed calls for a croc cull following the attacks weren't warranted.

"The question is: If you did cull, could you remove all the crocs? And the answer is no, you can't," he said.

"(Crocodiles) can travel hundreds of kilometres over a few days."

But Katter's Australian Party Queensland MP Shane Knuth said the new management strategy didn't go far enough and his party would draft legislation to go before state parliament to allow a controlled cull.

"This is much more important than politics. This is about the risk factors," Mr Knuth told AAP.

"Once we were able to even fish beside our waterways, that is now a risk.

"So we really need to make a decision on whether we're going to look after the interests and safety of people, or back the crocodiles."

Mr Knuth said the proposed legislation would include measures for a cull and a bounty system, as well as allowing indigenous groups to run croc-hunting safaris.

KAP plans to introduce the bill in May, but is unlikely to receive support from the Labor government.

Cassowary Coast mayor John Kremastos also expressed concern about the recent attacks, saying the Johnstone River used to be safe to swim in.

But despite his concerns with the new management strategy, Mr Kremastos didn't believe a cull was necessary.